Inductive components such as inductors and transformers are used in many fields of technology, for example in the automotive industry. There, conductor plate components such as power electronics, in which so-called momentum transformers or pulse transformers are used to control the gate of an electronic switching element, are used in automobile electronics. A “gate drive transformer” is a pulse transformer that controls the timing of power MOSFETs or IGBTs in switching power supplies (“Switch-mode-power-supply” or SMPS) as shown for example in the publication “A guide to designing gate drive transformers”, power electronics technology, 2007: 32 to 36, by Patrick Scoggins.
Gate-drive transformers usually have a coil that is supported by a coil body that may be formed both as surface-mountable (SMD) components or as through-hole components. In this, safety standards that require, inter alia, compliance with insulation and creepage paths shall be complied with just as for general electric and electronic components. The requirements for creepage and insulation paths are normally complied with by ensuring the coil bodies to be cast with a casting compound in a housing.
During the equipment of conductor plates with inductive components, reflow soldering processes are implemented to connect, inter alia, inductive components with conductor plates electrically and mechanically. In this, high temperatures arise during the soldering processes so that a component is frequently exposed to temperature fluctuations of 100° C. or more during the manufacturing process. Due to the varying expansion coefficients among the different materials in inductive components, for example among the casting compound, the coil body, the ferrite core and the winding, there will also be different thermal expansions as a consequence that lead to tensions in the material and ultimately to breakage. In many cases, for example the casting compound breaks, whereby the creepage and air paths of an inductive component are strongly reduced so that the standard requirements according to IEC/UL etc. may no longer be complied with.
A component may be exposed to further temperature fluctuations during operation. For example automobile electronics in close proximity to the engine are also exposed to high temperature fluctuations of −40° C. to +155° C. or more during operation. Furthermore, electric and electronic components of automobile electronics are subject to high mechanical stresses due to shock effects.
Based on the situation explained above, a coil body for an inductive component in which the disadvantages described above are eliminated shall be provided.